Mat processing equipment



Jan; 8, 1963 c. T. LARSEN ETAL 3,072,774

m PROCESSING EQUIPMENT Filed Jan. 18. 1960 2 Sheets-Sheet 1 INVENTORSCHARLES T. LARSEN DAVID 0. Mc GRAW ATTORNEYS Jan. 8, 1963 c. 'r. LARSENETAL 3,072,774

mxr PROCESSiNG EQUIPMENT Filed Jan. 18, 1960 -2 SheetS-Sheet 2 FIGS.FIG-7- FIG5." FIGJO.

as Hf PS 8 TIMER u FIG. I I. DAVID cmc GRAW hired This invention relatesto newspaper matrix (hereafter called mat) processing equipment, andmore particularly to an improved stereotype mat scorcher or roaster.

The newspaper industry operates in a complex series of deadlines andpractically all operations'in the publishing of a newspaper arecarried'out 'on a tight time schedule. Much duplication of machinery isnecessary'to assure the rigid time schedule is met since a failure ofany one of the machines which are links in the chain of operations inthe printing of a paper will stop the entire operation. One of thecritical steps in the process is the preparation of the stereotype matsfrom which printing castingsare made of a lead alloy hereafter calledstereotype metal.

A stereotype mat before processing is a flat laminated sheet of papierma-che-like material inclusive of a substantial moisture content tobetter enable it toreceive and retain a-n'impression from an assembledand completed printers form. The actual impression is made by passingthe mat in association with the printers form through a press under asufiicient pressure to produce a clear impression. Subsequently the matis pretreated in a vacuum drier and has a curved configuration impartedto it. next steps are directed towards forming a stereotype metalcasting from the mat. In order to make a good casting it isnecessary'that the mat be completely dry and'uniformly heated to atemperature compatible with molten stereotype metal. This isaccomplished by a scorcher.

It is necessary that the mats treated on a scorcher produce clear,precise, and exact castings so that there will be sharp reproduction inprinting. Areas of partieular difficulty are photographs, comic strips,illustrations and the .like, which in the trade are termed half-tones.

Present commercially available scorchers'have a tend ency to produce anonuniform temperature gradient across the mats. Mat temperaturesprocessed by such equipment will vary'fro-m relative coolness near theedges to higher temperatures towards the center.

' Furthermore, the present commercially used scorchers require longperiod-s of time, up to about forty minutes, to preheat to initialoperating conditions of about 350 F. These scorchers use 'strlpheaterslas a heat source and are usually thermostatically controlled. 7With thermostatically controlled scorchers there is normally a. widevariance from high to low temperature. Strip heaters are fiat,tube-"like sheaths encompassing a metallic electrical resistance elementpacked in a high melting point sand or powder such as TiO perature, thethermostatic control stops the flow of electricity and'the temperaturestarts to drop due to a convection effect resulting from the passage ofair around the strips. Inforder to maintain the desired temperature thethermostat causes a repassage of current through the strips. Since thesestrip heaters are slowheating and cooling elements, the continual.re-occurrence of these actions results in the above-mentioned variancein temperature-s.

As pointed out before, it takes approximately forty minutes for ascorcher using strip heaters to reach the initial operating temperatureofabout 350 F.; and after the treatment of one mat, a recovery time isrequired before a subsequent mat may be treated.

The problems discussed above are undesirable in that a temperaturegradient results in poor mats, i.e., not uni- The v Upon reaching thedesired teming and/or area coolness.

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formly heated across their surfaces, and castings made from such matshaveaporous, mottled and congealed surface. If a casting with thesesurface characteristics is usedon the presses, blots and masses of inkresult rather than the precise and sharp reproduction desired.

Also, in treating a stereotype mat in strip heater type scorchers, whenthe mats. reach a point where further eating may cause area burning,they must then be removed'and because of the frequent uneven roasting ofthe mat, there may still be moisture present. When the mat containsmoisture, contact with molten stereotype metal may cause rather violentsteam explosions, resulting in spraying of molten metal, endangeringpersonnel working with the mats.

Thus, where the first heat treatment results in an improperlyconditioned mat producing a chilled casting, having a porous, mottledand congealed surface, it has to be thrown away and a new one made,resulting in delay and lost production time. If this second or thirdcasting is also faulty, the lost time increases. If an imperfect matcannot produce a satisfactory casting, then a new stereo-- type matwould have to be made with a resultant time consuming and expensivedelayin making the casting.

Recently in the newspaper industry, there has been developed what istermed no-pack stereotype mats. These mats are about one-eighth of aninchin thickness and consist of a plurality of paper lamina inclusive ofclay filler and moisture. With this new relatively thick mat and presentstrip heater type scorchers, it is necessary that heat be imparted tothe mat at a relatively slow rate to dry the mat throughout itsthicknessand to prevent burn- Using the strip heater type scorcher it takes overfour minutes to properly condition and treat a no-pack mat. invention,it is possible to treat such mats in from thirty to sixty seconds.

Comparing the prior trade scorchers and the problems encountered intheir use with a scorcher according to our invention; it is possible toreach initial operating conditions with our scorcher within about fiveminutes of the.

it is possible to allow a mat to remain in the device without danger ofburning; there is a thorough drying throughout the thickness of the mateliminating the possibility of steam explosions; and there is an evenheating over the entire surface, eliminating area chilling of castingand/ or burning-of mats.

I Briefly, our invention consists of the use of a plurality of series oftubular quartz lamps as infra-red ray emitters better described as anincandescent element enclosed in an'evacuated tubular glass sheath,reflectors, a suitable housing, and surface upon which a mat may beplaced. The foregoing, in combination with a timing device, will enablethose skilled in the trade to overcome the previously noted shortcomingsof present commercially used scorchers in a manner which will becomemore obvious from the description presented hereafter.

It is, therefore, among the objects and advantages of our invention toprovide an improved newspaper stereotype mat scorcher which uniformlyitreats such mats both across their surfaces and through theirthicknesses; and accomplishes a superior treatment in a greatlydecreased period of time than previously thought possible; and requiressubstantially no recovery time after each use;

Other objects and advantages will become obvious from a study of thedescription hereafter with reference to the appended exemplary drawings,in which:

FIG. 1 is an end elevation in partial section of .a scorcher accordingto our invention;

FIG. 2 is atop view of an arrangement of tubular infra With adeviceaccording to our.

FIG. 3 is an end detail of the device of FIG. 1;

FIG. 4 is an end detail of the device of FIG. 1 with the cover partiallyopen;

FIG. 5 is a side view of the device of FIG. 1 with the cover sectioned;

FIGS. 6l0 are details of the timer activating mechanism from on throughoff positions in its operating cycle;

FIG. 11 is a wiring diagram of the device of FIG. 1; and

FIG. 12 is an enlarged detail of FIG. 2.

FIG. 1 which shows an exemplary scorcher design according to ourinvention depicts a suitable floor supported frame which includes apower supply 11, magnetic switch 12, timer mechanism 13 and mat treatingarea 14 at a readily accessible working level.

The infra-red ray emitters 15 are heldin spaced position by such assupports above the reflectors 21 and 22 (better shown in FIG. 2) andbase member 32. An arched surface 23, preferably made of perforatedsheet metal, supports a sheet of asbestos 24 (better shown in FIGS. 3and 4) whereupon stereotype mats (not shown) may be placed fortreatment. A cover 25, pivotally held in position by the rod 26,internally carries a second sheet of asbestos 27. The cover is easilylifted by means such as handle 28. The lifting operation is aided bysuch as counterweight 99. Depending from the counterweight is a support35 carrying a cam 36 which is positioned to depress the timer actuatingbutton 37.

The placement of the infra-red ray emitters 15 is shown in FIG. 2 asconsisting of three series of two each, positioned above the reflectors21 and 22. Preferably the reflectors are made from corrugated, polishedsheet metal. Because the elongated tubular design of the infra-redemitters, rays are propagated around a 360 angle, the reflectors arespaced beneath the emitters a distance suflicient to assuresubstantially complete reflection of the downwardly directed raysupwardly through the mat being treated. Also, because of the 360 raypropagation configuration, in combination with the reflectors, it ispossible to use a planar arrangement as opposed to an arched mounting,close to the mat holding surface, as required with use of strip heaters.

The schematic wiring diagram of FIG. 11 shows power being supplied atall times, when the device is on, to the two center emitters, a, b,while current to the other four emitters is controlled by the action ofthe magnetic switch 12 in conjunction with timer 13.

FIGS. 6-10 are illustrative of the cycle of operation by which when thecam 36 is allowed to pass the timer actuating button, when the cover isopened without depressing the button, and upon closing of the cover, thecam is locked against the bumper 38 and caused to depress the button 37thereby causing a surge of electricity to pass to the outside emittersthereby raising the temperature in a manner that will be described indetail hereafter.

Operation The power source is connected to a suitable supply of electriccurrent (not shown) by such as plug 34. Upon closing of switch 33 thedevice is turned on causing the center emitters a, b, to be activated.After the device reaches an operating temperature of about 270 F., aperi 0d of about five minutes, a stereotype mat to be treated is placedon the asbestos sheet 24. The cover 25 and the surface 23 and theasbestos sheets 24 and 27 carried thereby, respectively, are shaped toconform to the normal shaping of the stereotype mats and spaced apartsufficiently to allow a firm pressure to be uniformly exerted over thesurface of a mat placed between them.

After placement of the mat, the cover is closed. As the coveris loweredthe counterweight moves the support and cam 36 across the activatingbutton 37 thus closing the circuit to the four outside emitters andstarting the timer. A surge of about ten seconds duration to the outsideemitters causes the temperature to rise about 60 F. over a period ofabout thirty seconds thereby gradually raising the temperature from 270F. to about 330 F. Thereafter there is a gradual cooling back to thestandby temperature of 270 F. A mat has been left in a scorcheraccording to our invention as long as five minutes without burning,which is one of the desirable safety factors achieved by our scorcherwhich was not obtainable in the present commercially available stripheater type scorchers discussed previously.

After the thirty-second heat treatment, the mat is removed and is usedto form one side of a mold for a stereotype metal casting and anothermat may be heated immediately, no recovery time being necessary.

The strip heater type scorchers discussed above have no operationsimilar to our ten-second surge period; take at least seventy seconds toheat the first mat, require one-half to two minutes before subsequentmats may be treated in addition to the seventy-second period for actualtreatment, and have a fixed temperature level which requires constantsupervision to prevent burning of the mats.

Stereotype mats for comic strips have been a particular problem with thestrip heatertype scorcher since comic mats are thinner and morediflicult to cast and are only cast once, multiple castings beingunnecessary. Our scorcher will condition a comic mat in about fortyseconds.

Another feature of a scorcher according to our invention is that thetimer may be correlated with the speed, skill and efiiciency with whichthe man using its is able to Work.

It is anticipated, of course, that other arrangements of emitters thanthose shown in our exemplary arrangement may be used which wouldaccomplish our invention such as, for example, three elongated emitters.

Having described one manner of practicing our invention, it is desiredthat it be understood that we do not desire to be limited to theparticular design set forth herein, but rather by the scope of theappended claims.

We claim:

1. A newspaper stereotype mat scorcher inclusive of a base member havingmeans for reflecting infra-red rays directed toward the base toward amat supporting surface and a mat carried thereby, a plurality of seriesof elongated tubular infra-red ray emitters supported on said basemember spaced above said reflecting means, mechanically operable switchmeans associated with the scorcher arranged to periodically activatesome of the series of emitters and means arranged to provide continuousactivation for the remainder, and timing means interconnected with saidswitch means arranged to periodically automatically activate only saidsome of the series through predetermined time intervals upon initiationof the scorching of a mat.

2. A newspaper stereotype mat scorcher inclusive of a base member havingmeans for reflecting infra-red rays directed toward the base toward amat-supporting surface and a mat carried thereby, a plurality ofelongated tubular infra-red ray emitters supported on said base memberspaced above said reflecting means, means arranged to provide continuousactivation of a portion of the emitters, and second means inclusive oftiming means for periodically activating only the remaining emittersthrough predetermined time intervals upon initiation of the scorching ofa mat.

3. A newspaper stereotype mat scorcher inclusive of a base carryingmeans having a substantially planar upper reflecting surface arranged toreflect infra-red rays directed toward the base toward a supportingsurface and a mat carried thereby, a cover supported on the base memberarranged to be positioned in close proximity to the mat supportingsurface upon closure, a plurality of elongated tubular infra-red rayemitters supported on said base member spaced above said reflectingmeans, and

-on said frame above said working surface, the working surface and coverhaving opposed heat resistant surfacing and shaped to'hold a stereotypemat under uniform pressure across its surface, the plurality of seriesof emitters being spaced above a reflecting surface and supported bysaid frame, at least one series of emitters continuously in closedcircuit relative to the power source and the remaining of the pluralityof series of emitters in circuit with the magnetic switch and the timeras well as the power source such that the activation of the timer closesthe magnetic switch and thus completes a circuit whereby the otherseries of emitters are activated for a period of time determined by thetimer setting and thereafter the circuit is broken, and means toactivate the timer mount ed on the cover. 1 p

5. The apparatus of claim 4 in which the emitters are elongated, airtight, evacuated, tubular transparent sheaths enclosing elongatedincandescent type elements capable of propagating infra-red raysradially through an angle of 360.

6. In a newspaper stereotype matscorcher inclusive of an'arcuate workingsurface arranged for registry of a similarly shaped stereotype mat'to bescorched and a movable cover therefor which conforms in shape to theworking surface, the improvement which comprises a plurality ofelongated, air tight, evacuated, tubular transparent sheaths eachenclosing at least one elongated incandescent-type element capable ofpropagation infra-red rays through an angle of 360 through the sheathrelative to its longitudinal axis, all of said emitters being spacedlysupported above a planar reflecting surface below the working surfacewhereby said infra-red rays propagated 6' through an angle of 360 aresubstantially all directed through the working surface and a matfcarriedthereby, means interconnected with at least some of the emittersarranged to be activated upon closing of the cover to temporarilyactivate the emitters with which it is interconnected.

7. A newspaper mat scorcher comprising a frame, a power source, switchmeans and a timer all mounted on said frame, a plurality of series ofelongated tubular infrared ray emitters mounted on said frame below aworking surface supported thereby, and a cover mounted on said frameabove said working surface, the working surface and the cover havingopposed heat resistant surfaces and a shaped to hold a stereotype matunder a uniform pressure across its surface, the plurality of series ofemitters being spaced above a reflecting surface and supported by saidframe, at least one series of emitters continuously in closed circuitrelative to the power source and the remaining of the plurality ofseries of emitters in circuit with the switch means and the timer aswell as the power source such that the activation of the timer closesthe switch means and completes a circuit whereby the other series ofemitters are activated for a period of time determined by the timersetting and thereafter the circuit is broken, and means to activate thetimer operatively interconnected with the cover.

References Cited in the file of this patent UNITED STATES PATENTS1,135,473 Vath Apr. 13, 1915 2,454,334 Moir Nov. 23, 1948 2,535,268Coats Dec. 26, 1950 2,542,654 Gadden Feb. 20, 1951 2,612,594 Schubert eta1 Sept. 30, 1952 2,731,733 Griner Jan. 24, 1956 2,919,119 Vyverberg etal, Dec. 29, 1959 2,935,594 Christenson May 3, 1960 2,957,973 TorrezOct. 25, 1960 FOREIGN PATENTS 738,031 Great Britain Oct. 5, 1955

3. A NEWSPAPER STEREOTYPE MAT SCORCHER INCLUSIVE OF A BASE CARRYING MEANS HAVING A SUBSTANTIALLY PLANAR UPPER REFLECTING SURFACE ARRANGED TO REFLECT INFRA-RED RAYS DIRECTED TOWARD THE BASE TOWARD A SUPPORTING SURFACE AND A MAT CARRIED THEREBY, A COVER SUPPORTED ON THE BASE MEMBER ARRANGED TO BE POSITIONED IN CLOSE PROXIMITY TO THE MAT SUPPORTING SURFACE UPON CLOSURE, A PLURALITY OF ELONGATED TUBULAR INFRA-RED RAY EMITTERS SUPPORTED ON SAID BASE MEMBER SPACED ABOVE SAID REFLECTING MEANS, AND MEANS ARRANGED TO PROVIDE CONTINUOUS ACTIVATION TO AT LEAST ONE SERIES OF EMITTERS, SECOND MEANS FOR AUTOMATICALLY ACTIVATING THE REMAINING EMITTERS THROUGH PREDETERMINED TIME INTERVALS, AND MEANS CARRIED ON SAID COVER ARRANGED TO ACTIVATE THE SECOND MEANS. 